The SAE J1939 Communication Protocol has been in existence for a number of years in the United States. Vehicle manufacturers such as those that make chassis for refuse vehicles and others use Parameter Group Numbers (PGNs) which are each associated with eight bytes of data which are normally broken into a suspect parameter number groups (SPNs). Maps are provided by that industry standard provider to identify which set of numbers corresponds to particular sets of information relative to the vehicle.
For hypothetical example purposes only, Parameter Group No. 1234 could be associated with engine information such as RPM, oil pressure, and oil temperature, broken up into values within the eight bytes of data associated with that PGN as SPNs at specific locations in that order of eight bytes. Within the J1939 communication protocol, there are standard PGNs and proprietary PGNs. The standard PGNs range from 000000 to 00FEFF. The proprietary PGNs range from 00FF00 to 00FFFF.
For CANopen communications, there are certainly profiles which can be adopted (or not) by various users such as a garbage truck profile for assigning various IDs to data.
These IDs have bytes of data associated therewith. What if a particular manufacturer wanted to attempt to make it very difficult for competitors to copy or utilize their data? For instance, some companies would prefer to make their data incompatible with replacement parts provided by other manufacturers.
The applicant is unaware of any current techniques utilized in the automotive communications industry for intentionally making communication protocol data extremely difficult to decipher. Today one could simply look at data in the proprietary use PGNs and implement a change in the body (i.e., move the arm control joystick, extend the grabber arm, dump a can, etc.) and watch the SPNs change associated with those PGNs. Unassigned or unused PGNs would not likely have SPNs changing values during such operation.
Accordingly, a perceived need for making data as used across vehicle communication networks difficult to reverse engineer so as to be able to make replacement components, sensors or compatible modules which may be inferior in quality to those provided by the applicant.